How are Drugs Developed?

I wanted to write a post titled “What is a Clinical Research Associate?” However, I though it would be of more benefit to more people if I first described how drugs are developed. So here goes! When a new chemical compound is discovered the compound has to under go 4 processes before it is allowed to be marketed for human consumption:

Pre-clinical

Clinical Phases I, II, III

New Drug Application

Post Marketing Surveillance (Phase IV)

1. Pre-clinical This the laboratory aspect of drug development. There are a number of tests done to determine if the new compound is toxic to any organs or cells. These tests are done either within isolated cells (using in vitro methods) or in animal models (using in vivo methods). This is all done to see if the compound is safe to test in human beings. The information gathered from pre-clinical testing is submitted to regulatory authorities in the respective country. In the US the FDA requires pharmaceutical companies with new compounds to submit Investigational New Drug (IND) applications. Once the IND is approved the compound moves on to the Clinical Phase. 2. Clinical Phases

Phase I clinical trials are usually in healthy volunteers. These types of study are done to determine safety and dosing

Phase II clinical trials are used to study the drug efficacy ( the ability of a drug to produce the desired result ) and further determine safety in numbers of sick patients

Phase III clinical trials are larger than Phase II trials. These trials determine safety and efficacy in a larger numbers of patients with the sickness the drug is meant to treat

3. New Drug Application If the new drug emerges from the 3 Phases of clinical trials and has demonstrated to have the desired effect in target patients, it can be submitted for marketing approval in the various countries where it will be sold. In the US, this process is called a New Drug Application or NDA. If the NDA is approved the drug can be marketed for public use.4. Post Marketing Surveillance (Phase IV) Phase IV trial is also known as postmarketing surveillance. Phase IV trials involve the ongoing safety surveillance of a drug after it receives approval to be sold. This is because the drug will now be used in a larger population and more harmful effects (Adverse Events) may be discovered that were not seen in Phase I-III. These by Phase IV trials may result in a drug no-longer being sold. I hope this helps you get a general understanding of what “Clinical Research” is. In my next post I will illustrate specifically where the Clinical Research Associate fits into this equation. -Sara

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